DFRobot Gravity – An Offline Voice Recognition Module for Arduino, Raspberry Pi, ESP32

DFRobot Gravity – An Offline Voice Recognition Module for Arduino, Raspberry Pi, ESP32


The DFRobot Gravity is an offline voice recognition module, that can process up to 121 fixed and 17 customizable command words without internet connectivity. Designed for integration with Arduino, Raspberry Pi, and ESP32 platforms, it supports I2C and UART communication for diverse applications in smart home systems and interactive projects.

The module includes unique and user-friendly features including a self-learning function, supports 17 custom commands like whistles or meows, and has noise resistance for audio projects. For example, it can auto-feed pets on hearing a cat’s meow. It also has a user-friendly design with 121 pre-set commands for easy interaction, such as automatically closing windows during rain without manual input.

The voice recognition module features a dual mic for clear recognition of noise, built-in and external speaker support for instant feedback, and compatibility with I2C and UART, making it versatile for various 3.3V or 5V devices like Arduino and Raspberry Pi, ideal for smart homes and robotics.

Offline voice recognition offers quick responses without needing an internet connection while safeguarding privacy with fixed commands. But the only limitation is its fix choice of words. Online voice recognition, on the other hand, is more adaptable and developer-friendly but requires a stable internet connection and incurs higher costs, with response times tied to network speed.

DFRobot Gravity Module Specification:

  • The self-learning function enables voice command customization
  • Supports I2C and UART communication with Gravity interface
  • Compatible with both 3.3V and 5V logic levels
  • Comes with 121 pre-set command words for ease of use
  • Built-in speaker and external speaker interface for real-time feedback
  • Features power (red) and recognition status (blue) indicators
  • The dual microphone setup enhances noise resistance and recognition range
  • Compatible with popular platforms like Arduino, Raspberry Pi, and ESP32
  • Operating Voltage: 3.3 – 5V, with a max current of ≤370 mA (5V)
  • I2C Address: 0x64 for easy integration
  • Allows for 17 custom command additions
  • Includes a dedicated learning activation command
  • Onboard microphone sensitivity set at -28db
  • Compact module size: 49×32 mm/1.93×1.26 inches
  • Operates within a temperature range of 0-70℃

The company showcases projects such as Smart Waiter, a voice assistant for restaurants, and Home Automation on its store page. if you are thinking about purchasing one for yourself the module costs $16.90 on DFRobot’s products page. More details are available on the wiki page.

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About Debashis Das

Tech Content Creator | Hardware Design Engineer | IoT Enthusiast | Digital Storyteller | Video Creator | From crafting digital dialogues at Semicon Media to orchestrating online engagement at Electronics-lab.com, my journey is about making tech talk interesting and accessible. In the quiet corners of the day, I advocate for easier tech education, one tutorial at a time. Let's connect and keep the digital dialogue going!

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